The article “Electrical Characterization of Solid State Ionic Memory Elements” by Symanczyk, Balakrishnan, Gopalan, Happ, Kozicki, Kund, Mikolajick, Mitkova, Park, Pinnow, Robertson and Ufert, published in 2003 in “Proceedings NVMTS 2003”, pages 16ff, discloses a memory arrangement of the generic type. The article also discloses a method for programming memory cells of the CBRAM type. It should be mentioned in this case, by way of explanation, that the term “Ionic Memory Element” and also the term “Programmable Metallization Cell” (abbreviated to “PMC”) are generally used in the article to denote the term “CBRAM” (“Conductive Bridging” RAM) that is used in the present case. Since the fundamentals of how memory cells of the CBRAM type are constructed, of the chemicophysical processes on which their operation is based and of how they need to be operated in order to able to store information in them (=in order to be able to program them) have already been prepublished in the article, this information will be assumed to be generally known in specialist circles in the text below and will not be explained again in detail.
The article has likewise already disclosed that it is highly problematic to define and then comply with the electrical parameters of such memory cells when programming the latter. In particular, applying a voltage or voltage pulses which cause a memory cell to be “changed over” (=programmed) from a high nonreactive resistance (typical values for this are of the order of magnitude of 1010 to 1012 ohms) to a low nonreactive resistance (typical values for this are of the order of magnitude of 104 to 106 ohms) makes it necessary to monitor the flow of current (which occurs in the process) very closely and to limit it to a value at which a respective memory cell does not sustain any damage, not even in the form of degradation damage (which is usually noticeable only at a very much later date). In the abovementioned article, programming is apparently effected using current limiting. The disadvantage of this, however, is that current-limiting circuits generally operate only in a relatively inaccurate manner, with the result that exact compliance with programming parameters is not ensured. As a result of these inaccuracies, the specific properties of memory cells of the CBRAM type can be precalculated and complied with during practical operation only in a very inaccurate manner.
Furthermore, memory elements of the CBRAM type and also their operation are also presented in more detail in the article “Can Solid State Electrochemistry Eliminate the Memory Scaling Quandary?” by Kozicky, Mitkova, Zhu, Park and Gopalan, published in 2002 in “Proceedings of IEEE-NANO 2002”.